If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You may have to register
before you can post: click the register link above to proceed. To start viewing messages,
select the forum that you want to visit from the selection below.

Time and Relativity.

"Time is what a clock measures." -

I am sure we are all familiar with Einstein's famous definition of time; but what does it mean?
Every clock measures some sort of change, whether it is a clock’s movement(pendulum/subatomic changes) or part of the clock’s environment(sundial).

In an environment that is totally inert - (In which nothing is changing, even at the subatomic level) would any time pass? If nothing is changing, there is nothing for a clock to measure, so any clock would be 'stopped' or 'frozen in time'.

Place a clock in such an environment and time would pass because of the changes taking place within the clock - the clock's 'movement'. It will measure time generated by the changes that are part of the clock.
So is time generated by change?

All changes are governed by scientific laws; therefore time must be generated at the same rate in identical clocks subject to the same environmental conditions, (Einstein's first postulate)
and, based upon the constancy of the speed of light c, (Einstein's second postulate) the time measured for identical changes, in identical conditions, obeying identical scientific laws, must be the same in any inertial frame of reference. So how does a clock moving inertially run slow?

Because of Relativity.

Relativity, the viewing and measuring of mechanical processes in system, K', moving relative to observers in system K.

It is because of the motion of the clock's System, K', relative to the observer's system, K. A clock at rest in its own frame measures proper time when read from its frame, while an observer in another frame relative to which the clock is moving, measures coordinate time for that moving clock.

There are then two measures of the time read on the clock in a system. Proper time measured by the system’s own, local, clock at rest in that system, K', and Coordinate time measured against the local clock in an observer’s system, K, relative to which the system K’ is moving.

The Spacetime, or Invariant, Interval between two events is the same for all observers. It is the proper interval, read objectively by an observer for whom the clock is moving using the 'rods and clocks' of the moving system; or, by using the 'rods and clocks' from the observer's own system, they may read the moving clock subjectively - adding (by vector addition) the transit time of the measured System K', relative to the observer's System K, to give the coordinate time.

Coordinate Time is a Subjective measure made from another system, K, using the clock in system K.
Proper Time is an Objective measure that can be made remotely from anywhere, by any observer, using the rods and clocks of the measured system, K’. An objective measure takes no account of the location, nor the motion, of the observer.

Surely one of the main reasons for Einstein’s Theories of Relativity, was to recognize that measurements are fundamentally Subjective.

Definition of Time

Time is generated by intervals in processes of change.

Time is a measure of the duration of change. Time is generated by any process of change.

I am sure we are all familiar with Einstein's famous definition of time; but what does it mean?
Every clock measures some sort of change, whether it is a clock’s movement(pendulum/subatomic changes) or part of the clock’s environment(sundial).

In an environment that is totally inert - (In which nothing is changing, even at the subatomic level) would any time pass? If nothing is changing, there is nothing for a clock to measure, so any clock would be 'stopped' or 'frozen in time'.

Place a clock in such an environment and time would pass because of the changes taking place within the clock - the clock's 'movement'. It will measure time generated by the changes that are part of the clock.
So is time generated by change?

All changes are governed by scientific laws; therefore time must be generated at the same rate in identical clocks subject to the same environmental conditions, (Einstein's first postulate)
and, based upon the constancy of the speed of light c, (Einstein's second postulate) the time measured for identical changes, in identical conditions, obeying identical scientific laws, must be the same in any inertial frame of reference. So how does a clock moving inertially run slow?

Because of Relativity.

Relativity, the viewing and measuring of mechanical processes in system, K', moving relative to observers in system K.

It is because of the motion of the clock's System, K', relative to the observer's system, K. A clock at rest in its own frame measures proper time when read from its frame, while an observer in another frame relative to which the clock is moving, measures coordinate time for that moving clock.

There are then two measures of the time read on the clock in a system. Proper time measured by the system’s own, local, clock at rest in that system, K', and Coordinate time measured against the local clock in an observer’s system, K, relative to which the system K’ is moving.

The Spacetime, or Invariant, Interval between two events is the same for all observers. It is the proper interval, read objectively by an observer for whom the clock is moving using the 'rods and clocks' of the moving system; or, by using the 'rods and clocks' from the observer's own system, they may read the moving clock subjectively - adding (by vector addition) the transit time of the measured System K', relative to the observer's System K, to give the coordinate time.

Coordinate Time is a Subjective measure made from another system, K, using the clock in system K.
Proper Time is an Objective measure that can be made remotely from anywhere, by any observer, using the rods and clocks of the measured system, K’. An objective measure takes no account of the location, nor the motion, of the observer.

Surely one of the main reasons for Einstein’s Theories of Relativity, was to recognize that measurements are fundamentally Subjective.

Definition of Time

Time is generated by intervals in processes of change.

Time is a measure of the duration of change. Time is generated by any process of change.

Problem #2 with the OP's idea is that there is no place in thi universe without contiuous change. The sea of neutrinos and random quantum evebts ensures that.

Last edited by John Mendenhall; 2017-Apr-27 at 09:56 PM.

I'm not a hardnosed mainstreamer; I just like the observations, theories, predictions, and results to match.

"Mainstream isn’t a faith system. It is a verified body of work that must be taken into account if you wish to add to that body of work, or if you want to change the conclusions of that body of work." - korjik

Time is that which is measured by a clock. This is a sound way of looking at things. A quantity like time, or any other physical measurement, does not exist in a completely abstract way. We find no sense in talking about something unless we specify how we measure it. It is the definition by the method of measuring a quantity that is the one sure way of avoiding talking nonsense about this kind of thing.

This is fairly obvious. Physical quantities are abstracted in physics. The time on a clock is not the time coordinate in a Minkowski diagram.

We could start with a universe containing just a clock, observe that time passes, take away the clock and note that no laws of physics change. There is still time. What changes is the ability to measure time.

Originally Posted by TyroJack

...Time is generated by intervals in processes of change.

The "intervals" part of that assertion does not follow. Clocks suggest that time passes continuously. We have not reached any limits yet in building more and more accurate clocks (smaller and smaller "intervals").
Relativity explicitly states that time is continuous as is space. No matter how small an interval we look at in relativity, there is always a smaller interval.

I have seen numerous assertions in Wiki articles etc. claiming this is something Einstein said - possibly in his arguments/discussions with Henri Bergson a famous philosopher; but I have not pinned it down yet... Yet it does seem to be accepted as a common saying that is oft quoted...

Originally Posted by Reality Check

We could start with a universe containing just a clock, observe that time passes, take away the clock and note that no laws of physics change. There is still time. What changes is the ability to measure time.

But that is exactly what I am saying. If there were a universe containing just a clock... time would only pass while the clock was there, for the mechanism of the clock would involve a 'process of change', which the clock measures in order to measure the time it is generating. If there were no clock, in a totally empty/inert universe no time would be generated. The laws of physics would still apply just the same and if anything were to change it would change according to the Laws of Physics and time would be generated according to those laws.
I am saying that time only happens when something is changing.

Originally Posted by Reality Check

The "intervals" part of that assertion does not follow. Clocks suggest that time passes continuously. We have not reached any limits yet in building more and more accurate clocks (smaller and smaller "intervals").
Relativity explicitly states that time is continuous as is space. No matter how small an interval we look at in relativity, there is always a smaller interval.

Problem #2 with the OPs idea is that there is no place in thi universe without contiuous change. The sea of neutrinos and random quantum evebts ensures that.

True. But my argument is about the nature of time...

It is that time is generated by change. Chnage is continuous and therefore time is continuous, which is what is experienced.

Consider: time is experienced in any inertial frame of reference according to the same laws of Physics. Measured on a stationary clock by an adjacent observer this is proper time.
Time measured in a frame of reference moving relative to an observer, has the additional process of change of the moving frame of reference. The time generated by the movement of the frame of reference is separate from and does not affect the time measured within that frame of reference; but to the observer of the moving frame, more time is generated. This additional time is added (by vector addition) to the proper time in the frame of reference to give the coordinate time measured by the observer.

It is that time is generated by change. Chnage is continuous and therefore time is continuous, which is what is experienced.

This is just a restatement of Mach's second principle:-
"It is utterly beyond our power to measure the changes of things by time. Quite the contrary, time is an abstraction at which we arrive by means of the changes of things."

Change is varied and variable (depending on which change you measure and under what circumstances). Time isn't.

In relativity, time is just a geometric dimension equivalent to those of space. This requires no change for time to exist.

I would rather say the opposite. That change is governed by scientific laws which determine exactly how change proceeds and how much time is generated.

Time only exists when something is changing whether that be on a cosmic scale or a sub-atomic scale. If no change is happening time cannot be measured because all measures of time are comparisons against measures of the duration of some standard change that is used to set the time scale.

In a totally inert or totally empty space time cannot be measured. If one were to introduce a clock, the clock mechanism is constantly changing and therefore generating the time the clock measures...

So it is not the changes that generate time, it is something else that generates both time and change?

I would rather say that the scientific Laws govern how time is generated. Every time we write a scientific equation that commences t= (where t represents time) we are expressing how time is generated by whatever process the equation describes.

Originally Posted by Strange

While it is probably true that time cannot be measured in the absence of change, that does not mean that time doesn't exist in the absence of change.

True indeed. But if time cannot be measured then is it not equally an abstraction to say that it does exist. Does this not come down to what it is agreed is the nature of time?
And the only way we have of detecting the passage of time is by measuring the duration of changes.

Time is frequency quanta ^v^V we observe and associate with sine-wave pattern

Negative geodesic curved space )( is dark energy.

Positive and negative geodesically curved space embrace's sine-wave time as outer and inner surface of torus.

True non-occupied space embraces our finite, occupied space Universe ergo Universe of non-observed time as gravity and dark energy and the observed time associated with sine-wave pattern associated with all particles, atoms if not also molecules.

The above is the simplistic versions of two kinds of time. The more complex versions begin with molecules and their aggregate collection as humans that result in access to abstract time.

Animals other than humans have a sense of time, to whatever degree. They to do not have access to more complex aspects of abstract time.

I would rather say that the scientific Laws govern how time is generated. Every time we write a scientific equation that commences t= (where t represents time) we are expressing how time is generated by whatever process the equation describes.

But each of those equations will describe a different rate of change or time; so why doesn't time depend how we measure it?

True indeed. But if time cannot be measured then is it not equally an abstraction to say that it does exist. Does this not come down to what it is agreed is the nature of time?
And the only way we have of detecting the passage of time is by measuring the duration of changes.

In GR you can have a vacuum (empty) solution to the Einstein Field Equations. Even with nothing to measure time, it still exists as one of the dimensions of space-time.

I think is not a fair conclusion if others want to disscuss all aspects of time and complex set of associations to it. imho ebuc

In your first ATM thread you were warned and infracted against arguing moderation in the thread, instead of using the allowed response through PM, report, or feedback forum. Heavier infraction issued.

____________"Dumb all over, a little ugly on the side." -- Frank Zappa"Your right to hold an opinion is not being contested. Your expectation that it be taken seriously is." -- Jason Thompson"This is really very simple, but unfortunately it's very complicated." -- publiusModerator comments in this color | Get moderator attention using the lower left icon:
Recommended reading:Forum Rules * Forum FAQs * Conspiracy Theory Advice * Alternate Theory Advocates Advice

That is not what I wrote.
A universe with only a clock = time exists, passes and can be measured.
Take away the clock and the laws of physics do not change. Time still exists and passes.
Time is not "generated" by the clock. Time exists independently of whether there is s clock or not. That independently existing time is measured by the clock.

What the laws of physics say is that time happens even if nothing changes.

I am sure we are all familiar with Einstein's famous definition of time; but what does it mean?
Every clock measures some sort of change, whether it is a clock’s movement(pendulum/subatomic changes) or part of the clock’s environment(sundial).

In an environment that is totally inert - (In which nothing is changing, even at the subatomic level) would any time pass? If nothing is changing, there is nothing for a clock to measure, so any clock would be 'stopped' or 'frozen in time'.

Place a clock in such an environment and time would pass because of the changes taking place within the clock - the clock's 'movement'. It will measure time generated by the changes that are part of the clock.
So is time generated by change?

All changes are governed by scientific laws; therefore time must be generated at the same rate in identical clocks subject to the same environmental conditions, (Einstein's first postulate)
and, based upon the constancy of the speed of light c, (Einstein's second postulate) the time measured for identical changes, in identical conditions, obeying identical scientific laws, must be the same in any inertial frame of reference. So how does a clock moving inertially run slow?

Because of Relativity.

Relativity, the viewing and measuring of mechanical processes in system, K', moving relative to observers in system K.

It is because of the motion of the clock's System, K', relative to the observer's system, K. A clock at rest in its own frame measures proper time when read from its frame, while an observer in another frame relative to which the clock is moving, measures coordinate time for that moving clock.

There are then two measures of the time read on the clock in a system. Proper time measured by the system’s own, local, clock at rest in that system, K', and Coordinate time measured against the local clock in an observer’s system, K, relative to which the system K’ is moving.

The Spacetime, or Invariant, Interval between two events is the same for all observers. It is the proper interval, read objectively by an observer for whom the clock is moving using the 'rods and clocks' of the moving system; or, by using the 'rods and clocks' from the observer's own system, they may read the moving clock subjectively - adding (by vector addition) the transit time of the measured System K', relative to the observer's System K, to give the coordinate time.

Coordinate Time is a Subjective measure made from another system, K, using the clock in system K.
Proper Time is an Objective measure that can be made remotely from anywhere, by any observer, using the rods and clocks of the measured system, K’. An objective measure takes no account of the location, nor the motion, of the observer.

Surely one of the main reasons for Einstein’s Theories of Relativity, was to recognize that measurements are fundamentally Subjective.

Definition of Time

Time is generated by intervals in processes of change.

Time is a measure of the duration of change. Time is generated by any process of change.

That is not what I wrote.
A universe with only a clock = time exists, passes and can be measured.
Take away the clock and the laws of physics do not change. Time still exists and passes.
Time is not "generated" by the clock. Time exists independently of whether there is s clock or not. That independently existing time is measured by the clock.

What the laws of physics say is that time happens even if nothing changes.

My apologies, I misinterpreted what you were saying - my bad.

Yes, I agree one may argue that Time exists, as a dimension, even if nothing changes. But if nothing is changing does time increase or is it fixed, or 'frozen'? Is there any formula measuring time, t = (f), where the function does not represent some kind of change?

If nothing is changing there can be no measure of time, as there is nothing to measure. Time still exists as a dimension; but if nothing changes, it is 'frozen' at one point in time measured against whatever mechanism of change is being used to measure the changing time...

Yes, I agree one may argue that Time exists, as a dimension, even if nothing changes. But if nothing is changing does time increase or is it fixed, or 'frozen'? Is there any formula measuring time, t = (f), where the function does not represent some kind of change?

If nothing is changing there can be no measure of time, as there is nothing to measure. Time still exists as a dimension; but if nothing changes, it is 'frozen' at one point in time measured against whatever mechanism of change is being used to measure the changing time...

To repeat my earlier question, what if anything in your line of thought is contrary to the mainstream concepts of time as used by physicists?

Yes, I agree one may argue that Time exists, as a dimension, even if nothing changes. But if nothing is changing does time increase or is it fixed, or 'frozen'?

If nothing is changing then time is still "ticking" along at 1 second per second. That is basically the definition of a time coordinate. All you have done is remove the ability of an observer to measure time passing. So your ATM definition of time is less useful than mainstream physics where cosmology can describe an empty universe - vacuum solutions of GR.

To repeat my earlier question, what if anything in your line of thought is contrary to the mainstream concepts of time as used by physicists?

Hmm...

When I try to set out my understanding of time and relativity to check my understanding, the usual response is that I have it all wrong! So I find your question quite refreshing.

A pole lying on the ground has a length that is a property of the pole. Add another pole and the length increases - but the dimension in that direction continues on beyond the poles. A process of change, such as a clock's 'tick' has a duration. Add more ticks and the duration of the clock's ticking increases, but that duration is limited by the clock's ticks even though the time dimension continues. The time measured can only be what has happened, future time is yet to come...

If the process of change, the ticking of the clock were to stop - by the removal of the clock - and nothing was left that was changing, would time continue?
To take this a step further I would ask a further question: if the ticking clock was to be returned, could the interval without the clock be measured? I would opine that the interval where there was no clock could not be measured as there would be nothing to measure - there being nothing changing, no time could be measured to pass within that system.

If the time that we experience passing were to be interrupted: if time were frozen, then could we tell? If there were no way to measure it how can we say it does not happen?

It is an unrealistic situation that could never happen. But then so are all the rocket travelling at near the speed of light; at the speed of light; so far from anything that there are no external forces...

If there were no poles or anything else to measure, would the dimension in that direction continue to exist? I would not say either yes or no, but rather that the question becomes meaningless. Likewise with time. If there is no change, I would say that the question of whether or not time continues becomes meaningless.

We have innate senses of an object's position or size, and we describe those attributes in comparison with chosen reference objects, in three orthogonal space dimensions. We also have innate senses of change and of how fast or slow the change is. We describe before-and-after and fast-or-slow attributes in comparison with a suitable clock, in a time dimension. We have refined these dimension concepts into a mathematical construct that is logically sound and useful for scientific analysis. I think of time as a dimension or coordinate, not as an entity that fundamentally flows in a way that we measure. What we measure is the rate of change.

Is my line of thought mainstream? In four years as a physics major in college I never heard anyone address this issue.

Similar question - same answer. Once again you need to think of an empty universe where lengths exist but cannot be measured because there are no physical rulers in the universe. Ditto for time and clocks. Clocks measure time. Time as a dimension always exists.

Similar question - same answer. Once again you need to think of an empty universe where lengths exist but cannot be measured because there are no physical rulers in the universe. Ditto for time and clocks. Clocks measure time. Time as a dimension always exists.

Agree. Length as a dimension doesn't cease to exist just because there isn't a ruler in an otherwise vacant universe to measure it. Time doesn't cease to exist as a dimension just because there isn't a clock in an otherwise vacant universe to measure it.

Similar question - same answer. Once again you need to think of an empty universe where lengths exist but cannot be measured because there are no physical rulers in the universe. Ditto for time and clocks. Clocks measure time. Time as a dimension always exists.

I'm not sure if I totally agree. If the universe was completely empty then there would be no requirement for any laws, length or time. Dimensions of any sort would have no meaning.

Spacetime is a foundation in which events happen, not something that is created by events. Spacetime exists in an empty universe and the laws of physics do not vanish for an empty universe, e.g. GR has vacuum solutions.

Similar question - same answer. Once again you need to think of an empty universe where lengths exist but cannot be measured because there are no physical rulers in the universe. Ditto for time and clocks. Clocks measure time. Time as a dimension always exists.

Yes, "Time as a dimension always exists." but as you point out space as a dimension can exist, being the framework against which the length of bodies or spaces can be measured...
So, the dimension of time will exist as a 'scale' against which intervals in time, or durations can be measured...

Space and time, the dimensions of Spacetime are no more than an imagined framework providing structure to our concept of Spacetime, against which we can measure space and time.

Length is the spatial property that bodies possess.
Duration is a temporal property that processes of change possess.